A 27% Active-Power-Reduced 40-nm CMOS Multimedia SoC With Adaptive Voltage Scaling Using Distributed Universal Delay Lines

AVS technique for extremely scaled SoCs has been developed. To reduce design cost, we have developed a supply voltage control scheme employing universal delay line (UDL), rather than a replica delay line, for monitoring the critical path delay (T CRIT ). The UDL can be used in any product without any need for customizing. In addition, averaging the results of distributed 4 monitors with a pitch of 3 mm in a chip can reduce errors due to within-die variation by half. With these techniques, proposed scheme produces equivalent or less error to T CRIT than does a conventional scheme that uses a single critical path replica as a delay monitor, even with simple monitor design. We have shown that 40-nm CMOS SoCs using our AVS can reduce active power by 27%.